1. Technology Field
The present invention generally relates to a hybrid storage apparatus and a hybrid storage medium controller and an addressing method thereof, and more particularly, to a hybrid storage apparatus which uses both a non-volatile memory module and a hard disk module as its storage media and a hybrid storage medium controller and an addressing method thereof.
2. Description of Related Art
Non-volatile memory (for example, flash memory) is broadly used for storing data due to its characteristics such as data non-volatility, low power consumption, small volume, and non-mechanical structure. For example, a solid state drive (SSD) is a storage apparatus which uses a non-volatile memory as its storage medium. Compared to the conventional hard disk, flash memory offers higher access speed. In particular, a computer system having a flash memory as its primary hard drive (i.e., the hard drive for installing operating system) has much better performance than a computer system having a conventional hard disk as its primary hard drive.
However, compared to flash memory, conventional hard disk has longer lifespan and larger capacity. To be specific, a flash memory can only be erased (or written) for a limited number of times. When data is repeatedly written into a physical block of a flash memory for over a specific number of times, the physical block cannot be used for writing data any more. In particular, when a flash memory is used as the primary hard drive for installing an operating system in a computer system, because data of the operating system is frequently accessed during the operation of the computer system, the lifespan of the flash memory is far shorter than that of a conventional hard disk. In addition, the cost of unit capacity of the conventional hard disk has been greatly reduced along with the development of the hard disk technology. Thus, a hard disk having a much larger capacity can be purchased at the same cost as a flash memory.
Since flash memory and conventional hard disk respectively have their disadvantages as described above, a hard disk having a flash memory as a cache is developed to improve the performance of hard disk. However, in such a hard disk, the flash memory is only used for storing data temporarily so as to allow the controller of the hard disk to respond to a host system instantly, and the controller still needs to move data from the flash memory into corresponding disk addresses.
Thereby, how to improve the performance of a storage apparatus and prolong the lifespan thereof has become a major subject in the industry.
Nothing herein should be construed as an admission of knowledge in the prior art of any portion of the present invention. Furthermore, citation or identification of any document in this application is not an admission that such document is available as prior art to the present invention, or that any reference forms a part of the common general knowledge in the art.